Waterproof pressure sensor, and manufacturing method and sensor conveyance body for manufacturing waterproof pressure

Abstract

A waterproof pressure sensor includes a pressure detection element, a cavity package configured to be provided with a recess in which the pressure detection element is mounted and an edge provided around the recess, a frame configured to be attached to the edge of the cavity package and has a surface more smoothed than the edge and an opening, a contact prevention member configured to be attached to the frame, and a pressure introducing hole having a diameter smaller than a diameter of the opening at a position overlapping the opening, and a gel agent configured to be provided in the recess and the opening, in which the gel agent is provided to be separated from an edge of the pressure introducing hole on the frame side.

What is claimed is: 
     
       1. A waterproof pressure sensor comprising:
 a pressure detection element; 
 a cavity package having a recess in which the pressure detection element is mounted, and an edge portion surrounding the recess; 
 a frame attached to the edge portion of the cavity package, the frame having an opening above the recess, and a surface which is more smoothed than a surface of the edge portion; 
 a contact prevention member attached to the frame, the contact prevention member having a pressure introducing hole provided above the opening, the pressure introducing hole having a diameter smaller than a diameter of the opening; and 
 a gel agent provided in the recess and the opening, 
 wherein the gel agent is separated from a lower edge of the pressure introducing hole on the frame side. 
 
     
     
       2. The waterproof pressure sensor according to  claim 1 ,
 wherein a shape of the opening in a plan view is a polygonal shape or a circular shape. 
 
     
     
       3. The waterproof pressure sensor according to  claim 1 , further comprising a component mounted in the recess, the component having a bonding wire connected thereto,
 wherein a vertex of a loop of the bonding wire is disposed inside the opening in a plan view. 
 
     
     
       4. The waterproof pressure sensor according to  claim 3 ,
 wherein the bonding wire in a plan view extends in a direction which is not orthogonal to a radial direction from the center of the opening. 
 
     
     
       5. The waterproof pressure sensor according to  claim 1 ,
 wherein a material of the cavity package is a ceramic. 
 
     
     
       6. The waterproof pressure sensor according to  claim 1 , further comprising:
 a circuit element connected to the pressure detection element, wherein the pressure detection element is mounted on the circuit element. 
 
     
     
       7. The waterproof pressure sensor according to  claim 1 , wherein the gel agent has an air-contacting upper surface having an area equivalent to an area of the opening, thereby providing a pressure sensing area greater than an area of the pressure introducing hole. 
     
     
       8. A method of manufacturing a waterproof pressure sensor, comprising:
 providing a cavity package having a recess and an edge portion surrounding the recess; 
 mounting a pressure detection element in the recess of the cavity package; 
 attaching a frame to the edge portion of the cavity package, the frame having an opening above the recess, and a surface more smoothed than a surface of the edge portion; 
 injecting a liquid agent into the recess through the opening of the frame so as to fill the recess and come into the opening; 
 gelling the liquid agent into a gel agent; and 
 attaching a contact prevention member having a pressure introducing hole to the frame such that the pressure introducing hole is disposed above the opening, the pressure introducing hole having a diameter smaller than a diameter of the opening. 
 
     
     
       9. The method of manufacturing a waterproof pressure sensor according to  claim 8 ,
 wherein in the injecting the liquid agent into the recess, the liquid agent is injected from a center of the opening. 
 
     
     
       10. A conveyance body for the waterproof pressure sensor according to  claim 1 , comprising:
 a first member having a plurality of depressions arranged in a length direction thereof; 
 a plurality of the waterproof pressure sensors according to  claim 1 , each disposed in corresponding one of the plurality of the depressions; and 
 a second member bonded to the first member so as to be peeled off therefrom, the second member covering the plurality of depressions. 
 
     
     
       11. The method of manufacturing a water proof pressure sensor according to  claim 8 ,
 wherein in the injecting the liquid agent into the recess, the liquid agent also fills the opening of the flame to an upper edge thereof, 
 and wherein, through the gelling the liquid agent into the gel agent, an upper surface of the gel agent becomes lower than the upper edge of the opening of the frame so as to form a gap between the upper surface of the gel agent and a lower edge of the pressure introducing hole of the contact prevention member. 
 
     
     
       12. The method of manufacturing a water proof pressure sensor according to  claim 8 ,
 wherein, after the gelling of the liquid agent into the gel agent, the gel agent has an upper surface which contacts air, the upper surface having an area equivalent to an area of the opening, thereby providing a pressure sensing area greater than an area of the pressure introducing hole.